Ex vivo generation of effective Epstein-Barr virus (EBV)-specific CD8+ cytotoxic T lymphocytes from the peripheral blood of immunocompetent Epstein Barr virus-seronegative individuals

BACKGROUND: Although readily accomplished from immunocompetent Epstein-Barr virus- (EBV) seropositive individuals, the effective ex vivo generation of EBV-specific cytotoxic T lymphocytes (CTL) from the peripheral blood mononuclear cells (PBMC) of EBV-seronegative subjects has proven to be a challenge. The focus of our study was to ascertain optimized culture conditions required for the ex vivo generation of EBV-reactive autologous CTL from the PBMC of EBV-seronegative volunteers. METHOD: Freshly isolated PBMC obtained from immunocompetent EBV-seronegative and -seropositive individuals were used to generate EBV-specific autologous CTL lines using both conventional and a novel, modified ex vivo culture technique. RESULTS: In contrast to responses observed in EBV-seropositives after two to three rounds of ex vivo stimulation, gamma-irradiated autologous lymphoblastoid cell lines (LCL) were incapable of eliciting an effective anti-EBV cytotoxic response when freshly-isolated PBMC from EBV-seronegative individuals were used as responders. Under these culture conditions, CD4+ T cells with preferential expression of the Th2-type cytokine IL-4 were predominantly expanded in the PBMC obtained from EBV-seronegative individuals. However, the addition of recombinant human (rh) IL-12 during the primary phase of ex vivo stimulation resulted in augmentation of EBV-specific cytolysis of autologous LCL by CD8+ T cells. Furthermore, there was down-regulation in the secretion of IL-4 and up-regulation in that of the Th1-type cytokine IFN-gamma by responder CD4+ and CD8+ T cells. CONCLUSIONS: Taken together these data suggest that the addition of rhIL-12 during the primary phase of ex vivo stimulation of freshly isolated PBMC from EBV-seronegative individuals results in skewing of the immune response predominantly towards a CD4+ Th1-type (IFN-gamma) with the generation of an efficacious CTL-mediated anti-EBV reactivity. This novel ex vivo approach for generating effective autologous EBV-specific CTL could be adopted to treat refractory post-transplant lymphoproliferative disorders, which may be encountered in EBV-seropositive-->EBV-seronegative organ transplant recipients. Additionally, these ex vivo generated anti-EBV T cells could also be infused perioperatively to enhance prophylactically immunity against EBV infection in high-risk EBV-seronegative organ allograft recipients.     

Does a single plasma phenylalanine predict quality of control in phenylketonuria?

A 1993 MRC working group on phenylketonuria suggested standardising blood phenylalanine measurements by taking blood samples at the same time each day. Since it is not known how representative of a 24 hour period a single phenylalanine concentration is, the aim of this study was to investigate the 24 hour variability of plasma phenylalanine in well controlled children with phenylketonuria. Sixteen subjects, 12 girls and four boys aged 1 to 18 years, had hourly venous blood samples collected for 13 hours between 09.00 and 21.00 on one day. Serial skin puncture blood specimens were then collected at 24.00, 03.00, and 06.00 within the same 24 hour period. All food and drink was weighed. The median variation in plasma phenylalanine concentration was 155 mumol/l/day, with a minimum of 80 and a maximum of 280. The highest concentration occurred in the morning between 6.00 and 9.00 in 63% of subjects; the lowest occurred between midday and midnight in 94%. Concentrations < 100 mumol/l occurred in 46% of children below 11 years, three having concentrations < 30 mumol/l for two, six, and seven hours respectively. Three of five subjects had concentrations above the MRC guidelines for 24% of the period studied. Except in two subjects, the blood concentrations did not rise in response to phenylalanine consumption. However, the greater the quantity of protein substitute taken between waking and the 16.00 specimen, the larger the decrease in daytime phenylalanine concentration (r = -0.7030) (p < 0.005). There is therefore wide variability in phenylalanine concentrations in a 24 hour period in children with phenylketonuria which is not reflected in a single observation. Further study is needed to investigate the effects of timing of protein substitute on the stability of phenylalanine concentrations.     

Multicore myopathy: respiratory failure and paraspinal muscle contractures are important complications

Three ambulant males with multicore myopathy, a rare congenital myopathy, are reported with nocturnal hypoventilation progressing to respiratory failure at the age of 9, 13, and 21 years. Deterioration in these individuals occurred over several months without any precipitating event. Patients had clinical evidence of nocturnal hypoventilation with hypoxaemia and hypercapnia. Forced vital capacity was significantly reduced (20 to 43% of predicted level). These parameters improved on institution of overnight ventilation using a BiPAP pressure support ventilator with face mask or nasal pillows with O2 saturation maintained above 90% overnight and an increase in forced vital capacity by as much as 100% (0.3 to 0.6 litres). This was matched by a symptomatic and functional improvement. Also present in these patients and not previously reported is the association of multicore myopathy with paraspinal contractures which produce a characteristic scoliosis described as a 'side-sliding' spine. This may be improved by spinal bracing or surgery.     

The last fifty years of neonatal surgical management

Neonatal surgical mortality has steadily fallen over the last five decades. Improved survival does not appear to be related to the introduction of new operative procedures. Most of the basic procedures were developed by 1960. Eight developments appear to be responsible: (1) The growth of pediatric surgery resulted in widespread availability of neonatal surgeons and dissemination of knowledge about newborn surgical emergencies. (2) The parallel growth of pediatric anesthesia, beginning in 1946, provided specialized intraoperative management of the neonate. (3) Understanding neonatal physiology is the key to successful management; major advances occurred between 1950 and 1970. (4) New inventions revolutionized patient care; the transistor (1947) made it possible for medical devices to sense, amplify and control physiologic responses and opened the communication and computer age. (5) Neonatal mechanical ventilation had a prohibitive mortality and was seldom utilized; the development of CPAP and a continuous flow ventilator in the 1970s allowed safe ventilatory support. (6) Total parenteral nutrition (1968) prevented starvation that frequently affected infants with major anomalies. (7) The effective treatment of infection began with the clinical use of penicillin (1941); antibiotics have reduced mortality but infants suffering from the septic syndrome have a prohibitive mortality; cytokine, proinflammatory agent research, and the development of anti-inflammatory and blocking agents in the 1980s have not affected mortality. (8) The establishment of newborn intensive care units (1960) provided an environment, equipment, and staff for effective physiologic management.     

Metal shelf for hip dislocation

Insertion of an internal metal prosthesis to replace a deficient superior acetabular margin in subluxating hips is a feasible and practical procedure. Such an operation can be more simple, more efficient, and less shocking than the conventional procedure.